What is the difference between the two loop below? (In terme of execution time )

Question

for (int x = 1; x < 10; x++) {
// some code
}

AND

x=1
while(x <10) {
// some code
x++;
}

Answer 1

There is no difference, they both generate the exact same assembly code ( no optimization ):

0000000000000000 <main>:
0: sub rsp,0x38
4: call 9 <main+0x9>
9: mov DWORD PTR [rsp+0x2c],0x1
10:
11: cmp DWORD PTR [rsp+0x2c],0x9
16: jg 1f <main+0x1f>
18: add DWORD PTR [rsp+0x2c],0x1
1d: jmp 11 <main+0x11>
1f: mov eax,0x0
24: add rsp,0x38
28: ret

Answer 2

the variable x can be used outside 'while loop' but for 'for loop' no (x declared in the for statement) ;)